With the rapid development of portable devices such as mobile phones, people have an increasing demand on functionality of the portable devices. For example, in order to improve entertainment function of music of a mobile phone, the electroacoustic device is also developing rapidly.
Generally, an ultra-linear miniature speaker of a relating portable device has a lower diaphragm with a symmetrical half-diaphragm structure. Due to limitation of a size of the portable device, the symmetrical half-diaphragm cannot satisfy the demands of a user on single contact mode.
Accordingly, it is necessary to provide a new miniature speaker to solve the above-mentioned problem.